what that does is, it slows down the metabolism and the ischemia, that is a lack of blood and oxygen that go to the muscle. you want to make sure you preserve the heart as best as possible. and arrestis infuse the heart, make it quiescent. most importantly, we cool it. when we do that, the metabolic rate slows down. once you remove an organ from the body, it starts to die. until you place it into a new recipient and revive the blood and start to circulate the nutrients and oxygen, the organ is dying. the clock starts to take. that is why we don't have a lot of time. as i mentioned, unlike organs like the liver and pancreas and kidneys, they have a little bit of a longer tolerance for ischemia. the heart and lungs are not so resilient.